In-group versus Out-group Preferences in Intergroup Conflict: An Experiment

Individuals participating in a group conflict have different preferences, e.g., maximizing their own payoff, maximizing the group’s payoff, or defeating the rivals. When such preferences are present simultaneously, it is difficult to distinctly identify the impact of those preferences on conflict. In order to separate in-group and out-group preferences, we conduct an experiment in which human in-group or out-group players are removed while keeping the game strategically similar. Our design allows us to study (i) how effort in a group conflict vary due to in-group and out-group preferences, and (ii) how the impact of these preferences vary when the two groups have explicitly different social identities. The results of our experiment show that the presence of in-groups enhances concern about individual payoffs. A further presence of out-groups moderates the concern for individual payoffs through an additional concern for own group payoffs. The negative effect of the in-group preferences and the positive effect of the out-group preferences are weaker when group members have a common social identity.